Fuel gauge is stuck on full when filing car but computer show wrong km . hyundaii 20 year 2013 .I THINK IT SENDER UNIT NOT WORKING ?

WELL IT IS A SIMPLE CIRCUIT MOST ARE

• BLOW FUSE
• BAD WIRING
• TANK SENDER DEAD.
• RARE BAD METER.

did you first SCAN the PCM to see what is up first/ (oops?)
THE FUEL GAUGE ON THIS CAR IS RUN BY THE IP CLUSTER BRAIN CPU. DIRECT TO THE GAUGE FUEL.
So if fails, just it not speedo. that means
the data is missing the serial data bus, (comms)
the fuel tank RACK has pump,filter and level POT sender all in one
so the sender there is bad,
simple it is, all else works and car drives.
The sensor is at X below,
the ECM connect to it only to do the EVAP tests never a full tank.
sender bad or wires to it bad. is MY CALL.
watch out 2001./02 is year they moved this sender to pump end.

Your float level is stuck or went bad. If you replaced the whole unit. You could have jammed it if not then it's a bad pump assembly

Sounds like the float sender unit in the petrol tank is stuck

gead short in the wire from the gauge to the sender unit
the gauge works by the variable resistance in the tank unit so when the gauge is full there is low resistance so the gauge reads full
reading full all the time indicates that there is power flowing through the gauge to a ground before the sender unit in the tank

The sending unit inside the fuel tank is defective.

Hi,it must be that the gauge or sender unit are faulty,check sender unit first.

A constantly full fuel gauge is usually caused by a short circuit on the sensor wire. Check the wiring by isolating the wire as near as possible to the fuel gauge. Measure with an Ohm meter between the wire and earth, the reading should be more than 10 and less than about 200k. A short is indicated by a reading of around 0 Ohms, depending on the accuracy of your meter.
A second possibility is the sender unit in the fuel tank which could be faulty, and then finally, and only finally, the head gauge could be faulty.

ZJ
what does it do now? stuck high, low. ,read off a bit. ? or what?
the tests are easy.
covered in the FSM 100% ( in a bad way)
see that here in chapter,called, "instrument panel"
chapter 8E.
page 5
as you can see the gauge is digital (CCD)
and the PCM (engine controller) sends fuel data to the gage via
the CDD data bus.
so the sender , may be telling the PCM wrong information.
I'd start there.
if your read page 5 it tells you the PCM sends, Empty stop data
to the gauge when the sender messes up.? DID YOURS?
does your low fuel warning lamp still work?
if not, that is clue 2 that the sender is BAD. if dead lamp.

that means sender bad, or wires TO it are bad, as in all cases, electrical..
In a real Jeep dealer, they use the DRB tool and read the sender
data directly and in 1 second, ahhh, it reads wrong.
then find the cause.
but us poor, sand crabs, we dont have DRB scanners.
we are not blessed.

but we are not helpless, not yet.
see the last chapter "wiring", see the fuel page. #
8w=20-3 (pdf 69)
see the sender
see the 2 wires,
see the colors. bingo.
what i do is, inplug the PCM (battery neg lug, disconneted)
the measure the resistance of the 2 wires.
DB-LG and BR-YL
PCM C2 -A4 and C1-c26

the sender is JUST a crude Rheostat (a wire wound var. resistor)
0 ohms (near is full) 100 (near is empty)]
if it reads infinity the line is bad. wires, connector all the way to the sender.

old data on older jeeps 86
73 ohms Empty 23 ohms 1/2 tank 10 ohms Full

1998
With float in up position, resistance should be 20 ohms. With float in down position, resistance should be 220 ohm
i dont have spec. on all years.
but it dont matter.
its near zero full
and near 100 to 200 empty
and infinity dead, they all wear out and go open circuit some day.
or the connector rusts 100:1 . over bad sender.
corrosion is no rare thing on cars.

1997 TJ
20 ohms - full
220 ohms - empty.

im scanning the internet finding others data.


96 GC

The same wires can be tested on the pump side to measure the resistance of the sending unit. A low resistance of 20-30 ohms would indicate a full tank and an empty tank should be around 260-300 ohms. If the sending unit resistance tests higher or open circuit the sending unit is bad.

well its either the wire between the tank and guage in dash or it is the gauge in the dash